Method and apparatus for controlling the termination of processes in response to a shutdown command

A method and apparatus for controlling the termination of one or more processes in an information handling system, such as UNIX processes running under the control of an UNIX operating system kernel, in response to a shutdown command. Processes may optionally register with a registration facility of the operating system kernel as permanent processes ineligible for process termination or as blocking processes entitled to advance notification of process termination. In response to receiving a shutdown command, a shutdown facility of the operating system kernel notifies each process that has registered as a blocking process of an impending shutdown. Upon the expiration of a predetermined time interval, the shutdown facility determines whether all of the processes that have registered as blocking processes have concurred in the shutdown, either by unregistering as blocking processes or by terminating. If all of the processes that have registered as blocking processes have concurred in the shutdown, the shutdown facility terminates processes that have not registered as permanent processes while allowing processes that have registered as permanent processes to continue to run. Otherwise, the shutdown facility aborts the shutdown without terminating any of the processes and generates a message identifying processes that have not concurred in the shutdown.